waterfall
n.— «Lawmakers use the term “waterfall” to describe surplus revenue. Hube worried there might be no water in this year’s waterfall.» —“House acts on spending, tax rates and fees” by Nancy Remsen in Montpelier Burlington Free Press (Vermont) Feb. 19, 2007. (source: Double-Tongued Dictionary)
Further reading
Nancy in Aurora, Colorado, asks: Is there a better term for one’s adult offspring than childrenor kids. The list of expressions she’s pondered includes adult child, progeny, offspring, man-child, woman-child, descendant, successor...
Chuck in Rutland, Vermont, has heard a phrase several times over the years that left him puzzled. If someone announces it’s late and they’re going to bed, and someone else questions that idea, the retiring one observes, Well, it’s...